Chevrolet Silverado / GMC Sierra. Manual — part 2390

VACUUM BRAKE BOOSTER CHECK VALVE AND/OR HOSE REPLACEMENT

5

Tip: Tighten the upper right vacuum brake booster nut first.

Tighten: 33 N.m (24 lb ft)

6

Master Cylinder Nut (Qty: 2)

Tighten: 33 N.m (24 lb ft)

7

Master Cylinder Assembly

Procedure

1. Without disconnecting the brake pipe fittings, carefully position the master

cylinder assembly aside and support with heavy mechanics wire or
equivalent.

2. Inspect the brake master cylinder to vacuum brake booster seal for damage

and replace if necessary.

3. Ensure the brake master cylinder to vacuum brake booster seal is properly

seated in the groove of the master cylinder.

8

Vacuum Brake Booster Hose Clamp

9

Vacuum Brake Booster Hose

10

Vacuum Brake Booster

Procedure

1. Disconnect the vacuum brake booster electrical connectors, if equipped.

2. Discard the vacuum brake booster gasket.

3. Install a new vacuum brake booster gasket.

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Fig. 35: Vacuum Brake Booster Check Valve and/or Hose Replacement
Courtesy of GENERAL MOTORS CORP.

BRAKE MASTER CYLINDER PRESSURE SENSOR REPLACEMENT (WITH RPO JL1 AND
WITHOUT JL4)

Callout

Component Name

Preliminary Procedures

1. Deplete the vacuum reserve in the vacuum booster by applying the brake pedal 3 times

or until the pedal becomes firm.

2. If equipped with the 4.8L, 5.3L, 6.0L, or 6.2L engine, remove the upper intake

manifold sight shield. Refer to Upper Intake Manifold Sight Shield Replacement .

1

Vacuum Brake Booster Hose Clamp

2

Vacuum Brake Booster Hose Clamp

3

Vacuum Brake Booster Hose

4

Vacuum Brake Booster Check Valve

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Fig. 36: Brake Master Cylinder Pressure Sensor Replacement (With RPO JL1 and
Without JL4)
Courtesy of GENERAL MOTORS CORP.

Callout

Component Name

Preliminary Procedures

1. Turn the ignition switch to the OFF position.

2. Apply the park brake.

CAUTION:

Refer to Brake Fluid Irritant Caution .

NOTE:

Refer to Brake Fluid Effects on Paint and Electrical Components Notice .

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado